Java tutorial
package com.lab47billion.appchooser; /** * Created by dell on 1/4/2016. */ /* * Copyright 2014 Bla olar * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import android.animation.ArgbEvaluator; import android.annotation.TargetApi; import android.content.Context; import android.content.res.ColorStateList; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.RectF; import android.os.Build; import android.os.Bundle; import android.os.Parcel; import android.os.Parcelable; import android.support.v4.text.TextDirectionHeuristicCompat; import android.support.v4.text.TextDirectionHeuristicsCompat; import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat; import android.support.v4.widget.ExploreByTouchHelper; import android.text.BoringLayout; import android.text.Layout; import android.text.TextPaint; import android.text.TextUtils; import android.util.AttributeSet; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.VelocityTracker; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.view.accessibility.AccessibilityEvent; import android.view.animation.DecelerateInterpolator; import android.widget.EdgeEffect; import android.widget.OverScroller; import android.widget.RelativeLayout; import java.util.List; /** * Created by Bla olar on 24/01/14. */ public class HorizontalPicker extends RelativeLayout { public static final String TAG = "HorizontalTimePicker"; /** * The coefficient by which to adjust (divide) the max fling velocity. */ private static final int SELECTOR_MAX_FLING_VELOCITY_ADJUSTMENT = 4; /** * The the duration for adjusting the selector wheel. */ private static final int SELECTOR_ADJUSTMENT_DURATION_MILLIS = 800; /** * Determines speed during touch scrolling. */ private VelocityTracker mVelocityTracker; /** * @see ViewConfiguration#getScaledMinimumFlingVelocity() */ private int mMinimumFlingVelocity; /** * @see ViewConfiguration#getScaledMaximumFlingVelocity() */ private int mMaximumFlingVelocity; private final int mOverscrollDistance; private int mTouchSlop; private CharSequence[] mValues; private View[][] mLayouts; private TextPaint mTextPaint; private BoringLayout.Metrics mBoringMetrics; private TextUtils.TruncateAt mEllipsize; private int mItemWidth; private RectF mItemClipBounds; private RectF mItemClipBoundsOffser; private float mLastDownEventX; private OverScroller mFlingScrollerX; private OverScroller mAdjustScrollerX; private int mPreviousScrollerX; private boolean mScrollingX; private int mPressedItem = -1; private ColorStateList mTextColor; private OnItemSelected mOnItemSelected; private OnItemClicked mOnItemClicked; private int mSelectedItem; private EdgeEffect mLeftEdgeEffect; private EdgeEffect mRightEdgeEffect; private float mDividerSize = 0; private float mNormalTextSize = -1; private float mSelectedTextSize = -1; private int mSideItems = 1; private TextDirectionHeuristicCompat mTextDir; //private final PickerTouchHelper mTouchHelper; /*set select item top padding */ private int topPadding = -1; private boolean isScrollingStart = false; private CharSequence subText; private Context _context; public HorizontalPicker(Context context) { this(context, null); _context = context; } public HorizontalPicker(Context context, AttributeSet attrs) { this(context, attrs, R.attr.horizontalPickerStyle); _context = context; } public HorizontalPicker(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); _context = context; // create the selector wheel paint TextPaint paint = new TextPaint(); paint.setAntiAlias(true); mTextPaint = paint; TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.HorizontalPicker, defStyle, 0); CharSequence[] values; int ellipsize = 3; // END default value int sideItems = mSideItems; try { mTextColor = a.getColorStateList(R.styleable.HorizontalPicker_android_textColor); if (mTextColor == null) { mTextColor = ColorStateList.valueOf(0xFF000000); } values = a.getTextArray(R.styleable.HorizontalPicker_values); ellipsize = a.getInt(R.styleable.HorizontalPicker_android_ellipsize, ellipsize); mDividerSize = a.getDimension(R.styleable.HorizontalPicker_dividerSize, mDividerSize); mNormalTextSize = a.getDimension(R.styleable.HorizontalPicker_normalTextSize, 20); mSelectedTextSize = a.getDimension(R.styleable.HorizontalPicker_selectedTextSize, -1); sideItems = a.getInt(R.styleable.HorizontalPicker_sideItems, sideItems); if (mNormalTextSize > -1) { setTextSize(mNormalTextSize); } if (mSelectedTextSize == -1) { mSelectedTextSize = mNormalTextSize; } } finally { a.recycle(); } switch (ellipsize) { case 1: setEllipsize(TextUtils.TruncateAt.START); break; case 2: setEllipsize(TextUtils.TruncateAt.MIDDLE); break; case 3: setEllipsize(TextUtils.TruncateAt.END); break; case 4: setEllipsize(TextUtils.TruncateAt.MARQUEE); break; } Paint.FontMetricsInt fontMetricsInt = mTextPaint.getFontMetricsInt(); mBoringMetrics = new BoringLayout.Metrics(); mBoringMetrics.ascent = fontMetricsInt.ascent; mBoringMetrics.bottom = fontMetricsInt.bottom; mBoringMetrics.descent = fontMetricsInt.descent; mBoringMetrics.leading = fontMetricsInt.leading; mBoringMetrics.top = fontMetricsInt.top; mBoringMetrics.width = mItemWidth; setWillNotDraw(false); mFlingScrollerX = new OverScroller(context); mAdjustScrollerX = new OverScroller(context, new DecelerateInterpolator(2.5f)); // initialize constants ViewConfiguration configuration = ViewConfiguration.get(context); mTouchSlop = configuration.getScaledTouchSlop(); mMinimumFlingVelocity = configuration.getScaledMinimumFlingVelocity(); mMaximumFlingVelocity = configuration.getScaledMaximumFlingVelocity() / SELECTOR_MAX_FLING_VELOCITY_ADJUSTMENT; mOverscrollDistance = configuration.getScaledOverscrollDistance(); mPreviousScrollerX = Integer.MIN_VALUE; setValues(values); setSideItems(sideItems); /*mTouchHelper = new PickerTouchHelper(this); ViewCompat.setAccessibilityDelegate(this, mTouchHelper);*/ } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int heightMode = MeasureSpec.getMode(heightMeasureSpec); int width = MeasureSpec.getSize(widthMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec); int height; if (heightMode == MeasureSpec.EXACTLY) { height = heightSize; } else { Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics(); int heightText = (int) (Math.abs(fontMetrics.ascent) + Math.abs(fontMetrics.descent)); heightText += getPaddingTop() + getPaddingBottom(); if (heightMode == MeasureSpec.AT_MOST) { height = Math.min(heightSize, heightText * 2); } else { height = heightText * 2; } } setMeasuredDimension(width, height); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); int saveCount = canvas.getSaveCount(); canvas.save(); int selectedItem = mSelectedItem; float itemWithPadding = mItemWidth + mDividerSize; // translate horizontal to center canvas.translate(itemWithPadding * mSideItems, 0); if (mValues != null) { for (int i = 0; i < mValues.length; i++) { mTextPaint.setColor(getTextColor(i)); // get text layout View layout = mLayouts[i][0]; // layout.draw(canvas); //NEW View layoutSub = mLayouts[i][1]; int saveCountHeight = canvas.getSaveCount(); canvas.save(); float x = 0; float lineWidth = 40f; if (lineWidth > mItemWidth) { if (isRtl(mValues[i])) { x += (lineWidth - mItemWidth) / 2; } else { x -= (lineWidth - mItemWidth) / 2; } } /*set select item top padding */ int yTranslate; if (!isScrollingStart && i == selectedItem) { mTextPaint.setTextSize(mSelectedTextSize); } else { mTextPaint.setTextSize(mNormalTextSize); } // translate vertically to center if (layoutSub != null) { yTranslate = (canvas.getHeight() - (layout.getHeight() + layoutSub.getHeight())) / 2; } else { yTranslate = (canvas.getHeight() - layout.getHeight()) / 2; } if (i == selectedItem && topPadding != -1) { yTranslate = topPadding; } canvas.translate(-x, yTranslate); RectF clipBounds; if (x == 0) { clipBounds = mItemClipBounds; } else { clipBounds = mItemClipBoundsOffser; clipBounds.set(mItemClipBounds); clipBounds.offset(x, 0); } canvas.clipRect(clipBounds); layout.draw(canvas); if (layoutSub != null) { Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics(); int heightText = (int) (Math.abs(fontMetrics.ascent) + Math.abs(fontMetrics.descent)); canvas.translate(-x, (layout.getHeight() + heightText - getTopPadding()) / 2); canvas.clipRect(clipBounds); layoutSub.draw(canvas); } // restore vertical translation canvas.restoreToCount(saveCountHeight); // translate horizontal for 1 item canvas.translate(itemWithPadding, 0); } } // restore horizontal translation canvas.restoreToCount(saveCount); drawEdgeEffect(canvas, mLeftEdgeEffect, 270); drawEdgeEffect(canvas, mRightEdgeEffect, 90); } @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1) @Override public void onRtlPropertiesChanged(int layoutDirection) { super.onRtlPropertiesChanged(layoutDirection); mTextDir = getTextDirectionHeuristic(); } /** * TODO cache values * * @param text * @return */ private boolean isRtl(CharSequence text) { if (mTextDir == null) { mTextDir = getTextDirectionHeuristic(); } return mTextDir.isRtl(text, 0, text.length()); } private TextDirectionHeuristicCompat getTextDirectionHeuristic() { if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) { return TextDirectionHeuristicsCompat.FIRSTSTRONG_LTR; } else { // Always need to resolve layout direction first final boolean defaultIsRtl = (getLayoutDirection() == LAYOUT_DIRECTION_RTL); switch (getTextDirection()) { default: case TEXT_DIRECTION_FIRST_STRONG: return (defaultIsRtl ? TextDirectionHeuristicsCompat.FIRSTSTRONG_RTL : TextDirectionHeuristicsCompat.FIRSTSTRONG_LTR); case TEXT_DIRECTION_ANY_RTL: return TextDirectionHeuristicsCompat.ANYRTL_LTR; case TEXT_DIRECTION_LTR: return TextDirectionHeuristicsCompat.LTR; case TEXT_DIRECTION_RTL: return TextDirectionHeuristicsCompat.RTL; case TEXT_DIRECTION_LOCALE: return TextDirectionHeuristicsCompat.LOCALE; } } } private void remakeLayout() { if (mLayouts != null && mLayouts.length > 0 && getWidth() > 0) { for (int i = 0; i < mLayouts.length; i++) { // mLayouts[i][0].replaceOrMake(mValues[i], mTextPaint, mItemWidth, // Layout.Alignment.ALIGN_CENTER, 1f, 1f, mBoringMetrics, false, mEllipsize, // mItemWidth); mLayouts[i][0] = LayoutInflater.from(_context).inflate(R.layout.performance_custom_layout, this, false); // if(subText != null) { // mLayouts[i][1] = new BoringLayout(subText, mTextPaint, mItemWidth, // Layout.Alignment.ALIGN_CENTER, 1f, 1f, mBoringMetrics, false, mEllipsize, mItemWidth); // } } } } private void drawEdgeEffect(Canvas canvas, EdgeEffect edgeEffect, int degrees) { if (canvas == null || edgeEffect == null || (degrees != 90 && degrees != 270)) { return; } if (!edgeEffect.isFinished()) { final int restoreCount = canvas.getSaveCount(); final int width = getWidth(); final int height = getHeight(); canvas.rotate(degrees); if (degrees == 270) { canvas.translate(-height, Math.max(0, getScrollX())); } else { // 90 canvas.translate(0, -(Math.max(getScrollRange(), getScaleX()) + width)); } edgeEffect.setSize(height, width); if (edgeEffect.draw(canvas)) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) { postInvalidateOnAnimation(); } else { postInvalidate(); } } canvas.restoreToCount(restoreCount); } } /** * Calculates text color for specified item based on its position and state. * * @param item Index of item to get text color for * @return Item text color */ private int getTextColor(int item) { int scrollX = getScrollX(); // set color of text int color = mTextColor.getDefaultColor(); int itemWithPadding = (int) (mItemWidth + mDividerSize); if (scrollX > itemWithPadding * item - itemWithPadding / 2 && scrollX < itemWithPadding * (item + 1) - itemWithPadding / 2) { int position = scrollX - itemWithPadding / 2; color = getColor(position, item); } else if (item == mPressedItem) { color = mTextColor.getColorForState(new int[] { android.R.attr.state_pressed }, color); } /* else if(item == mSelectedItem) { color = mTextColor.getColorForState(new int[]{android.R.attr.state_selected}, color); }*/ return color; } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); calculateItemSize(w, h); } @Override public boolean onTouchEvent(MotionEvent event) { if (!isEnabled()) { return false; } if (mVelocityTracker == null) { mVelocityTracker = VelocityTracker.obtain(); } mVelocityTracker.addMovement(event); int action = event.getActionMasked(); switch (action) { case MotionEvent.ACTION_MOVE: isScrollingStart = true; float currentMoveX = event.getX(); int deltaMoveX = (int) (mLastDownEventX - currentMoveX); if (mScrollingX || (Math.abs(deltaMoveX) > mTouchSlop) && mValues != null && mValues.length > 0) { if (!mScrollingX) { deltaMoveX = 0; mPressedItem = -1; mScrollingX = true; } final int range = getScrollRange(); if (overScrollBy(deltaMoveX, 0, getScrollX(), 0, range, 0, mOverscrollDistance, 0, true)) { mVelocityTracker.clear(); } final float pulledToX = getScrollX() + deltaMoveX; if (pulledToX < 0) { mLeftEdgeEffect.onPull((float) deltaMoveX / getWidth()); if (!mRightEdgeEffect.isFinished()) { mRightEdgeEffect.onRelease(); } } else if (pulledToX > range) { mRightEdgeEffect.onPull((float) deltaMoveX / getWidth()); if (!mLeftEdgeEffect.isFinished()) { mLeftEdgeEffect.onRelease(); } } mLastDownEventX = currentMoveX; invalidate(); } break; case MotionEvent.ACTION_DOWN: if (!mAdjustScrollerX.isFinished()) { mAdjustScrollerX.forceFinished(true); } else if (!mFlingScrollerX.isFinished()) { mFlingScrollerX.forceFinished(true); } else { mScrollingX = false; } mLastDownEventX = event.getX(); if (!mScrollingX) { mPressedItem = getPositionFromTouch(event.getX()); } invalidate(); break; case MotionEvent.ACTION_UP: isScrollingStart = false; VelocityTracker velocityTracker = mVelocityTracker; velocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity); int initialVelocityX = (int) velocityTracker.getXVelocity(); if (mScrollingX && Math.abs(initialVelocityX) > mMinimumFlingVelocity) { flingX(initialVelocityX); } else if (mValues != null) { float positionX = event.getX(); if (!mScrollingX) { int itemPos = getPositionOnScreen(positionX); int relativePos = itemPos - mSideItems; if (relativePos == 0) { selectItem(); } else { smoothScrollBy(relativePos); } } else if (mScrollingX) { finishScrolling(); } } mVelocityTracker.recycle(); mVelocityTracker = null; if (mLeftEdgeEffect != null) { mLeftEdgeEffect.onRelease(); mRightEdgeEffect.onRelease(); } case MotionEvent.ACTION_CANCEL: mPressedItem = -1; invalidate(); if (mLeftEdgeEffect != null) { mLeftEdgeEffect.onRelease(); mRightEdgeEffect.onRelease(); } break; } return true; } private void selectItem() { // post to the UI Thread to avoid potential interference with the OpenGL Thread if (mOnItemClicked != null) { post(new Runnable() { @Override public void run() { mOnItemClicked.onItemClicked(getSelectedItem()); } }); } adjustToNearestItemX(); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (!isEnabled()) { return super.onKeyDown(keyCode, event); } switch (keyCode) { case KeyEvent.KEYCODE_DPAD_CENTER: case KeyEvent.KEYCODE_ENTER: selectItem(); return true; case KeyEvent.KEYCODE_DPAD_LEFT: smoothScrollBy(-1); return true; case KeyEvent.KEYCODE_DPAD_RIGHT: smoothScrollBy(1); return true; default: return super.onKeyDown(keyCode, event); } } /* @Override protected boolean dispatchHoverEvent(MotionEvent event) { if (mTouchHelper.dispatchHoverEvent(event)) { return true; } return super.dispatchHoverEvent(event); }*/ @Override public void computeScroll() { computeScrollX(); } @Override public void getFocusedRect(Rect r) { super.getFocusedRect(r); // TODO this should only be current item } public void setOnItemSelectedListener(OnItemSelected onItemSelected) { mOnItemSelected = onItemSelected; } public void setOnItemClickedListener(OnItemClicked onItemClicked) { mOnItemClicked = onItemClicked; } public int getSelectedItem() { int x = getScrollX(); return getPositionFromCoordinates(x); } public void setSelectedItem(int index) { mSelectedItem = index; scrollToItem(index); } /** * @return Number of items on each side of current item. */ public int getSideItems() { return mSideItems; } public void setSideItems(int sideItems) { if (mSideItems < 0) { throw new IllegalArgumentException("Number of items on each side must be grater or equal to 0."); } else if (mSideItems != sideItems) { mSideItems = sideItems; calculateItemSize(getWidth(), getHeight()); } } /** * @return */ public CharSequence[] getValues() { return mValues; } /** * Sets values to choose from * * @param values New values to choose from */ public void setValues(CharSequence[] values) { if (mValues != values) { mValues = values; if (mValues != null) { mLayouts = new View[mValues.length][2]; for (int i = 0; i < mLayouts.length; i++) { // mLayouts[i][0] = new BoringLayout(mValues[i], mTextPaint, mItemWidth, Layout.Alignment.ALIGN_CENTER, // 1f, 1f, mBoringMetrics, false, mEllipsize, mItemWidth); mLayouts[i][0] = LayoutInflater.from(_context).inflate(R.layout.performance_custom_layout, this, false); this.addView(mLayouts[i][0]); // if(subText != null) { // mLayouts[i][1] = new BoringLayout(subText, mTextPaint, mItemWidth, Layout.Alignment.ALIGN_CENTER, // 1f, 1f, mBoringMetrics, false, mEllipsize, mItemWidth); // } } } else { mLayouts = new View[0][0]; } requestLayout(); invalidate(); } } @Override protected void onRestoreInstanceState(Parcelable state) { if (!(state instanceof SavedState)) { super.onRestoreInstanceState(state); return; } SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); setSelectedItem(ss.mSelItem); } @Override protected Parcelable onSaveInstanceState() { Parcelable superState = super.onSaveInstanceState(); SavedState savedState = new SavedState(superState); savedState.mSelItem = mSelectedItem; return savedState; } @Override public void setOverScrollMode(int overScrollMode) { if (overScrollMode != OVER_SCROLL_NEVER) { Context context = getContext(); mLeftEdgeEffect = new EdgeEffect(context); mRightEdgeEffect = new EdgeEffect(context); } else { mLeftEdgeEffect = null; mRightEdgeEffect = null; } super.setOverScrollMode(overScrollMode); } public TextUtils.TruncateAt getEllipsize() { return mEllipsize; } public void setEllipsize(TextUtils.TruncateAt ellipsize) { if (mEllipsize != ellipsize) { mEllipsize = ellipsize; remakeLayout(); invalidate(); } } @Override protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) { super.scrollTo(scrollX, scrollY); if (!mFlingScrollerX.isFinished() && clampedX) { mFlingScrollerX.springBack(scrollX, scrollY, 0, getScrollRange(), 0, 0); } } @Override protected void drawableStateChanged() { super.drawableStateChanged(); //TODO } private int getPositionFromTouch(float x) { return getPositionFromCoordinates( (int) (getScrollX() - (mItemWidth + mDividerSize) * (mSideItems + .5f) + x)); } private void computeScrollX() { OverScroller scroller = mFlingScrollerX; if (scroller.isFinished()) { scroller = mAdjustScrollerX; if (scroller.isFinished()) { return; } } if (scroller.computeScrollOffset()) { int currentScrollerX = scroller.getCurrX(); if (mPreviousScrollerX == Integer.MIN_VALUE) { mPreviousScrollerX = scroller.getStartX(); } int range = getScrollRange(); if (mPreviousScrollerX >= 0 && currentScrollerX < 0) { mLeftEdgeEffect.onAbsorb((int) scroller.getCurrVelocity()); } else if (mPreviousScrollerX <= range && currentScrollerX > range) { mRightEdgeEffect.onAbsorb((int) scroller.getCurrVelocity()); } overScrollBy(currentScrollerX - mPreviousScrollerX, 0, mPreviousScrollerX, getScrollY(), getScrollRange(), 0, mOverscrollDistance, 0, false); mPreviousScrollerX = currentScrollerX; if (scroller.isFinished()) { onScrollerFinishedX(scroller); } postInvalidate(); // postInvalidateOnAnimation(); // TODO } } private void flingX(int velocityX) { mPreviousScrollerX = Integer.MIN_VALUE; mFlingScrollerX.fling(getScrollX(), getScrollY(), -velocityX, 0, 0, (int) (mItemWidth + mDividerSize) * (mValues.length - 1), 0, 0, getWidth() / 2, 0); invalidate(); } private void adjustToNearestItemX() { int x = getScrollX(); int item = Math.round(x / (mItemWidth + mDividerSize * 1f)); if (item < 0) { item = 0; } else if (item > mValues.length) { item = mValues.length; } mSelectedItem = item; int itemX = (mItemWidth + (int) mDividerSize) * item; int deltaX = itemX - x; mAdjustScrollerX.startScroll(x, 0, deltaX, 0, SELECTOR_ADJUSTMENT_DURATION_MILLIS); invalidate(); } private void calculateItemSize(int w, int h) { int items = mSideItems * 2 + 1; int totalPadding = ((int) mDividerSize * (items - 1)); mItemWidth = (w - totalPadding) / items; mItemClipBounds = new RectF(0, 0, mItemWidth, h); mItemClipBoundsOffser = new RectF(mItemClipBounds); scrollToItem(mSelectedItem); remakeLayout(); } private void onScrollerFinishedX(OverScroller scroller) { if (scroller == mFlingScrollerX) { finishScrolling(); } } private void finishScrolling() { adjustToNearestItemX(); mScrollingX = false; // post to the UI Thread to avoid potential interference with the OpenGL Thread if (mOnItemSelected != null) { post(new Runnable() { @Override public void run() { mOnItemSelected.onItemSelected(getPositionFromCoordinates(getScrollX())); } }); } isScrollingStart = false; } private int getPositionOnScreen(float x) { return (int) (x / (mItemWidth + mDividerSize)); } private void smoothScrollBy(int i) { int deltaMoveX = (mItemWidth + (int) mDividerSize) * i; deltaMoveX = getRelativeInBound(deltaMoveX); mFlingScrollerX.startScroll(getScrollX(), 0, deltaMoveX, 0); invalidate(); } /** * Calculates color for specific position on time picker * * @param scrollX * @return */ private int getColor(int scrollX, int position) { int itemWithPadding = (int) (mItemWidth + mDividerSize); float proportion = Math.abs(((1f * scrollX % itemWithPadding) / 2) / (itemWithPadding / 2f)); if (proportion > .5) { proportion = (proportion - .5f); } else { proportion = .5f - proportion; } proportion *= 2; int defaultColor; int selectedColor; if (mPressedItem == position) { defaultColor = mTextColor.getColorForState(new int[] { android.R.attr.state_pressed }, mTextColor.getDefaultColor()); selectedColor = mTextColor.getColorForState( new int[] { android.R.attr.state_pressed, android.R.attr.state_selected }, defaultColor); } else { defaultColor = mTextColor.getDefaultColor(); selectedColor = mTextColor.getColorForState(new int[] { android.R.attr.state_selected }, defaultColor); } return (Integer) new ArgbEvaluator().evaluate(proportion, selectedColor, defaultColor); } /** * Sets text size for items * * @param size New item text size in px. */ private void setTextSize(float size) { if (size != mTextPaint.getTextSize()) { mTextPaint.setTextSize(size); requestLayout(); invalidate(); } } /** * Calculates item from x coordinate position. * * @param x Scroll position to calculate. * @return Selected item from scrolling position in {param x} */ private int getPositionFromCoordinates(int x) { return Math.round(x / (mItemWidth + mDividerSize)); } /** * Scrolls to specified item. * * @param index Index of an item to scroll to */ private void scrollToItem(int index) { scrollTo((mItemWidth + (int) mDividerSize) * index, 0); // invalidate() not needed because scrollTo() already invalidates the view } /** * Calculates relative horizontal scroll position to be within our scroll bounds. * * @param x Relative scroll position to calculate * @return Current scroll position + {param x} if is within our scroll bounds, otherwise it * will return min/max scroll position. */ private int getRelativeInBound(int x) { int scrollX = getScrollX(); return getInBoundsX(scrollX + x) - scrollX; } /** * Calculates x scroll position that is still in range of view scroller * * @param x Scroll position to calculate. * @return {param x} if is within bounds of over scroller, otherwise it will return min/max * value of scoll position. */ private int getInBoundsX(int x) { if (x < 0) { x = 0; } else if (x > ((mItemWidth + (int) mDividerSize) * (mValues.length - 1))) { x = ((mItemWidth + (int) mDividerSize) * (mValues.length - 1)); } return x; } private int getScrollRange() { int scrollRange = 0; if (mValues != null && mValues.length != 0) { scrollRange = Math.max(0, ((mItemWidth + (int) mDividerSize) * (mValues.length - 1))); } return scrollRange; } public int getTopPadding() { return topPadding; } public void setTopPadding(int topPadding) { this.topPadding = topPadding; } public void setSubText(CharSequence subText) { this.subText = subText; } public interface OnItemSelected { public void onItemSelected(int index); } public interface OnItemClicked { public void onItemClicked(int index); } public static class SavedState extends BaseSavedState { private int mSelItem; public SavedState(Parcelable superState) { super(superState); } private SavedState(Parcel in) { super(in); mSelItem = in.readInt(); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeInt(mSelItem); } @Override public String toString() { return "HorizontalPicker.SavedState{" + Integer.toHexString(System.identityHashCode(this)) + " selItem=" + mSelItem + "}"; } @SuppressWarnings("hiding") public static final Creator<SavedState> CREATOR = new Creator<SavedState>() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; } private static class PickerTouchHelper extends ExploreByTouchHelper { private HorizontalPicker mPicker; public PickerTouchHelper(HorizontalPicker picker) { super(picker); mPicker = picker; } @Override protected int getVirtualViewAt(float x, float y) { float itemWidth = mPicker.mItemWidth + mPicker.mDividerSize; float position = mPicker.getScrollX() + x - itemWidth * mPicker.mSideItems; float item = position / itemWidth; if (item < 0 || item > mPicker.mValues.length) { return INVALID_ID; } return (int) item; } @Override protected void getVisibleVirtualViews(List<Integer> virtualViewIds) { float itemWidth = mPicker.mItemWidth + mPicker.mDividerSize; float position = mPicker.getScrollX() - itemWidth * mPicker.mSideItems; int first = (int) (position / itemWidth); int items = mPicker.mSideItems * 2 + 1; if (position % itemWidth != 0) { // if start next item is starting to appear on screen items++; } if (first < 0) { items += first; first = 0; } else if (first + items > mPicker.mValues.length) { items = mPicker.mValues.length - first; } for (int i = 0; i < items; i++) { virtualViewIds.add(first + i); } } @Override protected void onPopulateEventForVirtualView(int virtualViewId, AccessibilityEvent event) { event.setContentDescription(mPicker.mValues[virtualViewId]); } @Override protected void onPopulateNodeForVirtualView(int virtualViewId, AccessibilityNodeInfoCompat node) { float itemWidth = mPicker.mItemWidth + mPicker.mDividerSize; float scrollOffset = mPicker.getScrollX() - itemWidth * mPicker.mSideItems; int left = (int) (virtualViewId * itemWidth - scrollOffset); int right = left + mPicker.mItemWidth; node.setContentDescription(mPicker.mValues[virtualViewId]); node.setBoundsInParent(new Rect(left, 0, right, mPicker.getHeight())); node.addAction(AccessibilityNodeInfoCompat.ACTION_CLICK); } @Override protected boolean onPerformActionForVirtualView(int virtualViewId, int action, Bundle arguments) { return false; } } }